The embodiment is directed to a fiber laser that can emit light at a desired wavelength.
As one of laser apparatuses for use in the fields of processing machines, medical devices, and measurement devices, for example, a fiber laser is known. A laser light emitted from this fiber laser is excellent in light condensation properties more than in laser lights emitted from other laser apparatuses, the laser light is of high power density, and the spot diameter can be made small. Moreover, since the fiber laser allows high-precision processing and can process a hard material that absorbs a laser light, the application is rapidly spreading in the field of processing machines specifically.
As one of the fiber laser, a resonator fiber laser is known in which a pair of mirrors is disposed as an amplification optical fiber is sandwiched between the mirrors (see JP-A-2010-56265). In the resonator fiber laser, in a pair of the mirrors, the reflectance of one mirror is higher than the reflectance of the other mirror, and the other mirror reflects light having at least a part of a wavelength in the wavelength of the light reflected off one mirror. A part of light resonating between one mirror and the other mirror is transmitted through the other mirror whose reflectance is low, and the light is emitted. Therefore, the wavelength of the outgoing light is defined by the reflected wavelength of the mirror
Patent Document 1: JP-A-2010-56265